Reciprocating pump and intake valve means therefor

ABSTRACT

An improved reciprocating pump is provided having an intake valve mechanism particularly useful in pumps intended for controlled or metered feed of liquid, wherein a valve assemblage incorporating a two part spring actuated movable valve member is detachably supported in a pump head in close proximity to the terminal end of a pump or piston chamber to thereby minimize the volume of communicating passages between said intake valve and pump chamber. By means of the two part construction of the movable valve member, the movable member can be mounted in the valve assemblage with the spring tensioning means remote from the valve head and connecting passages.

[ Apr. 23,1974

1 1 RECIPROCATING PUMP AND INTAKE VALVE MEANS THEREFOR [75] Inventor: Charles E. Sech, Brighton, Mich.

[73] Assignee: West Chemical Products, Inc., Long Island City, N.Y.

22 Filed: Apr. 7, 1972 211 App]. No.: 241,901

1 v i T FOREIGN PATENTS OR APPLICATIONS 671,251 9/1963 Canada ..4l7/568 962,514 4/1957 Germany 137/4544 Primary Examiner-William L. Freeh Assistant ExaminerLeonard Smith Attorney, Agent, or Firm-Howard E. Thompson, Jr.

[57] ABSTRACT An improved reciprocating pump is provided having an intake valve mechanism particularly useful in pumps intended for controlled or metered feed of liquid, wherein a valve assemblage incorporating a two part spring actuated movable valve member is detachably supported in a pump head in close proximity to the terminal end of a pump or piston chamber to thereby minimize the volume of communicating passages between said intake valve and pump chamber. By means of the two part construction of the movable valve member, the movable member can be mounted in the valve assemblage with the spring tensioning means remote from the valve head and connecting passages.

11 Claims, 4 Drawing Figures PATENTED 23 W4 Lab a;

INVENT R. GHARLEJESECH A TTOR/Vf Y RECIPROCATING PUMP AND INTAKE VALVE MEANS THEREFOR BACKGROUND OF THE INVENTION Reciprocating pumps incorporating a generally cylindrical piston and movable in a cylindrical pump chamher having associated intake and exhaust valve means constitutes one of the oldest basic mechanisms for controlled movement of fluids. Special problems arise, however, when it is desired to deliver accurately small measured or metered amounts of fluid by means of a reciprocating pump, particularly one intended to operate at high speed, i.e., more than about 150 to 200 reciprocations per minute, due to the size and volume of passages which may be needed to establish communication between the pump chamber and the intake and exhaust valves.

For reliable functioning of intake and exhaust valves in high speed pump operation, it is generally desirable to employ spring tensioned valves, and while spring tensioning of an exhaust valve presents little problem, it has heretofore been difficult to provide spring tensioning of an intake valve while at the same time minimizing the volume of the intake passage between the intake valve and pump chamber.

Typical examples of prior art approaches are shown in the following U.S. Pats; P. L. Scott, No. 1,572,045 issued Feb. 9, 1926, W. .l. Redman, No. 2,559,659 issued July 10, 1951, C. H. Jorgensen et al., No. 2,707,921 issued May I0, 1955, F. D. Lowther, Sr., No. 2,612,116 issued Sept. 30, 1952, R. Backofen et al., No. 2,373,642 issued Apr. 17, 1945, and C. A. Miller, No. 2,9l6,998 issued Dec. l5, I959. In each of these patents, several of which are intended for the accurate or metered delivery of fluids, it will be noted that a spring member is oriented between the seating portion of the intake valve and the pump chamber. The space necessarily provided for the sup-port and movement of such spring means inherently adds to the volume of the connecting passage between the intake valve and the pump chamber, whereas in the accurate metered delivery of fluid, it is important that this volume be maintained at a minimum. Thus, it will be apparent that the prior art approaches in the above mentioned patents fall far short of providing an optimum type of structure for intake valves in reciprocating pumps intended for accurate delivery of fluid in high speed operation.

THE INVENTION The shortcomings of the prior art are overcome by the improved pump and valve mechanism of the pres ent invention wherein a pump head is provided with a valve receiving recess closely adjacent the end of the pump or piston chamber having a small communicating passage therewith; and a preassembled intake valve mechanism detachably interfitting with said recess includes an axially movable two part valve member disposing a valve head and seat at the inner portion thereof and tensioning means for said valve at the outer portion thereof remote from the passage connecting with said pump chamber.

The intake valve body is of generally cylindrical contour having external rib and groove means facilitating the seating and sealing thereof in said recess and having an internal generally cylindrical bore of essentially uniform dimension throughout its length but having a restriction of reduced diameter at the inner or valve forming end thereof. A movable valve member which extends axially of said bore comprises a two-part structure. The outer part has a threaded portion extending through the restricted portion of the valve body, on which is mounted an internally threaded inner part having a shank adapted to fit within the restricted portion of said valve body, with ample space for fluid passage therebetween. Said inner part has an enlarged inner end of substantially greater diameter than the diameter of said restricted portion forming a valve head cooperating with a resilient valve seat in engagement with the inner end of said restriction.

A coil spring within the cylindrical bore externally of the restricted portion of said bore and having its free end keyed to the movable valve member normally supports the valve member in seating engagement while permitting deseating of the valve in the suction action of the pump. Means is also provided at the valve head for limiting its inward or opening movement, while at the same time maintaining open fluid passages to the pump cylinder.

Details of the improved reciprocating pump and intake valve means therefor will be readily understood from a consideration of the following description in conjunction with the accompanying drawing in which preferred adaptations of the invention have been illustrated with the various parts thereof identified by suitable reference characters in each of the views, and in which:

FIG. 1 is a sectional view through a pump head showing the reciprocating pump or piston member within the pump chamber and the association of intake and exhaust valves therewith.

FIG. 2 is a fragmentary broken sectional view substantially on the line 22 of FIG. 1.

FIG. 3 is a view similar to the lower portion of FIG. 1 showing a slightly modified form of intake valve construction; and

FIG. 4 is a fragmentary sectional view of a portion of the inlet valve assemblage as shown in FIG. 1 indicating a modified structure in the valve head portion thereof.

As shown in FIGS. 1 and 2 the improved pump and inlet valve structure of the present invention has been illustrated as applied to a pump body or casing 10 having a cylindrical recess 11 extending through one end 12 thereof and terminating at a closed end 13 providing a pump chamber 14 receiving a reciprocating piston or plunger 15 having suitable guide and sealing means 16 adjacent the end 12 of the pump casing.

For purpose of illustration, the guide and sealing means 16 has been shown as comprising a generally tubular member 17 having a smooth inner bore 18 closely but slidably engaging the plunger 15. The member 17 has a hub portion 19 including at its inner end an annular groove 20, and joining at its outer end an enlarged diameter flange 21. The member 17 fits within a stepped recess in the pump casing 10 having an outer large diameter shown at 22 receiving the flange 21, and intermediate reduced diameter as seen at 23 receiving the hub 19 and a further reduced diameter as seen at 24 in which is compressably arranged an annular resilient sealing member 25. The annular groove 20 supports a supplemental annular sealing member 26, and the member 17 is tensionally supported in the stepped recess by a snap ring 27 fitting within an enlarged diameter groove 28 in the outer recess 22 and bearing against the outer surface of the flange 21. It will be apparent that this structure provides for firm support and sealing of the piston while at the same time facilitating easy assemblage and disassemblage for periodic checking or replacement of the sealing members and 26.

In pumps for the accurate or metered feed of fluid, the piston 15 will be driven by means permitting adjustment of variables such as speed, length of stroke, and clearance between the piston and closed end 13 of the pump chamber in the terminal position of the piston. These details are not illustrated since they form no part of the present invention, but are mentioned merely as background for the following description of the valve mechanisms. It should be noted in this connection that a preferred use of the improved pump structure is for the controlled feed of small quantities of fluid to flowing fluid streams of substantial volume and that visualization of the size of the components involved can be better appreciated if it is borne in mind that the transverse dimension of the pump housing 10 as shown in FIG. 1 is approximately 1% inches and that all other parts are shown to a proportionate scale.

Closely adjacent the closed end 13 of the pump cylinder are radially disposed inlet and outlet passages 29 and 30 which communicate respectively with stepped recesses 31 and 32 which receive inlet valve assemblage 33 and outlet valve assemblage 34. Each of the stepped recesses includes an outer or large diameter bore 31a, 320 having a slightly larger diameter annular groove 31b, 32b therein, an intermediate diameter bore 310, 32c and a smaller diameter bore 31d, 32d.

The inlet and outlet valve assemblage 33 and 34 are essentially tubular members having at the inner ends thereof hub portions 33a, 34a fitting within the intermediate recesses 3lc, 32c and provided with annular grooves 33b, 34b which receive resilient sealing rings 35, 36. Outwardly of the hubs 33a, 340 are enlarged diameter flanges 33c, 34c fitting within the bores 31a and 32b and providing bearing surfaces by which snap rings 37, 38 fitting within the annular grooves 31b, 32b support the valve assemblages 33, 34 in the recesses 31, 32. Outer extremities of the valve assemblages include means as indicated by the threaded portions 33d and 34d respectively for detachably coupling fluid feed and exhaust lines to the pump assemblage.

Further considering the outlet valve assemblage 34, it will be noted that this includes a uniform diameter bore 39 extending through a major portion ofits length and a co-axial smaller diameter bore 40 at its outer end forming an internal shoulder 41 providing bearing support for a coil spring 42, the other end of which is in resilient engagement with a ball check valve 43, which in the closed position is in peripheral seating engagement with an annular resilient insert 44 within the small diameter bore 32d. It will be noted, in this connection, that the bore 39 of valve assemblage 34 is preferably co-axial with the port or passage 30 and, further, that the diameter of the ball valve 33 is sufficiently smaller than the bore 39 so that as fluid pressure forces the ball valve upwardly against the tension of the spring 42, the

full flow of fluid through the port 30 can freely pass around the ball check valve 43.

Considering now the intake valve assemblage 33, it will be noted that the tubular member contains a main bore 45 extending through a major portion of its length, a reduced diameter bore 46 in alignment with the hub 31c, and an enlarged diameter groove 47 adjacent thereto receiving an annular resilient valve seat 48.

Movable mounted in the bore 45, 46, 47 is a two-part valve member in which the inner part 49 is of generally tubular and internally threaded contour having an enlarged valve head 50 for engagement with the valve seat 48 and an elongated shank which extends through the reduced diameter bore 46 sufficiently spaced therefrom to provide free fluid passage therebetween. The outer valve part 51 is of elongated generally cylindrical contour with the main portion having a diameter generally corresponding to the diameter of the shank portion of the inner part 49 and including an externally threaded axial extension 52 in threaded engagement with the inner part 49. A coil spring 53 disposed between the outer valve part 51 and the bore 45 bears at its inner end against a shoulder formed at the reduced diameter bore 46 and is compressably supported at its lower end by a radially protruding portion 54 on the part 51 suitably provided by a split ring interfitting with an annular groove 55 on the part 51.

In the assemblage as shown in FIG. I, it will be noted that the groove 47 receiving the valve seat 48 termi nates short of the end of the valve assemblage 33 so that full support of the valve seat is provided by the valve assemblage itself. In the modification shown in FIG. 3 of the drawing in which the parts have been similarly numbered, it will be noted that the enlarged diameter bore 47 continues to the end of the tubular body of the valve assemblage and is partly supported and positioned by a shoulder 56 formed at the juncture between intermediate bore 31c and small bore 31d. While the latter form of construction has the advantage of greater ease of assemblage, the construction as shown in FIG. 1 is considered to be somewhat superior in performance because the valve seat 48 is in no way influenced by the axial pressure on the valve assemblage exerted by the clip ring 37.

As shown in FIGS. 1-3, the threaded extension 52 of the outer valve part protrudes beyond the valve head 50 to provide a bearing against the end of the small diameter bore 31d when the valve is in the open position, and with this construction, it will be apparent that the port 29 must be axially offset with respect to the axis of the valve member and its threaded extension 52. The protrudance of the threaded extension, when thus acting as a stop means, permits free passage of fluid moving through the open valve into and through the port 29.

The fragmentary showing in FIG. 4 in which the parts are similarly numbered where applicable, illustrates a slight modification wherein the port 29' is co-axial with the inner valve part 49 and the threaded extension 52 of the outer valve part, which in this instance, terminates within the valve head 50. The outer face of the valve head 50 is provided with radial grooves 57 which form, when the valve head is in bearing engagement with the base of small bore 31d, fluid passages freely communicating with the port 29.

With the various forms of construction shown in FIGS. 1, 3 and 4, it will be apparent that the volume of the space providing fluid passage from the valve seat 48 to the port 29 has been reduced to a bare minimum. while at the same time assuring proper and controlled seating of the valve head 50 under the action of the remotely arranged coil spring 53. With any of the forms of construction, the intake valve mechanism can be completely assembled and tested before the assemblage 33 is mounted in the pump housing 10. It will also be apparent that the device can readily be adapted to different desired operating conditions by disassembly and substitution of coil springs 53 of increased or decreased tension to thereby facilitate most efficient operation of the pump. In this connection, it might be noted that in a pump of the type described, the plunger may reciprocate at rates ranging from about l l to 500 strokes per minute, with each stroke delivering a measured small amount of liquid (generally less than about 0.002 cu. inch per stroke); and with this type of operation it will be apparent that accurate control of the operation of the intake valve, and ease of adapting its operation to varying conditions, are extremely important factors in achieving desired performance of the pump.

Various changes and modifications in the pump and valve construction herein disclosed may occur to those skilled in the art, and to the extent that such changes and modifications are embraced by the appended claims, it is to be understood that they constitute part of the present invention.

What is claimed is:

l. A pump mechanism comprising a housing forming an elongated closed end chamber having a piston closely engaging the side walls of said chamber and reciprocating toward and from said closed end, said housing having circumferentially spaced recesses extending radially of said chamber in alignment with the closed end thereof for detachably receiving inlet and outlet valve assemblages, said recesses communicating with said chamber through short radial passages having aligned sides coextensive with the closed end of said chamber, each of said valve assemblages including spring tensioned valve means having seating means closely adjacent the respective inlet and outlet passages, the spring tensioning means for both the inlet and outlet valves being disposed within the respective valve assemblage with the seating means between the tensioning means and the respective passages, orientation of the valve tensioning means in the intake valve assemblage being provided by a valve insert having a generally cylindrical bore extending therethrough with an annular restriction of reduced diameter adjacent the inner end of said bore providing the fluid passage of said intake valve, and an elongated valve member freely and axially movable in said bore, said movable member having an enlarged diameter valve head portion at the inner end thereof cooperating with the inner surface of said restriction to provide a valve seat, the opposite end of said member having radially extending means for tensionally engaging a coil spring arranged circumferentially of said member and in bearing engagement with the outer surface of the restriction in said bore, the bore of said intake valve insert receiving an annular resilient member in engagement with the inner surface of said restriction and providing a valve seat for engagement with the valve head portion of said axially movable member, and the bore of said intake valve insert having an annular recess of enlarged diameter adjacent the inner surface of said restriction providing interlocked engagement between said annular resilient member and said intake valve insert.

2. A pump mechanism comprising a housing forming an elongated closed end chamber having a piston closely engaging the side walls of said chamber and reciprocating toward and from said closed end, said housing having circumferentially spaced recesses extending radially of said chamber in alignment with the closed end thereof for detachably receiving inlet and outlet valve assemblages, said recesses communicating with said chamber through short radial passages having aligned sides coextensive with the closed end of said chamber, each of said valve assemblages including spring tensioned valve means having seating means closely adjacent the respective inlet and outlet passages, the spring tensioning means for both the inlet and outlet valves being disposed within the respective valve assemblage with the seating means between the tensioning means and the respective passages, orientation of the valve tensioning means in the intake valve assemblage being provided by a valve insert having a generally cylindrical bore extending therethrough with an annular restriction of reduced diameter adjacent the inner end of said bore providing the fluid passage of said intake valve, and an elongated valve member freely and axially movable in said bore, at the inner end thereof cooperating with the inner surface of said restriction to provide a valve seat, the opposite end of said member having radially extending means for tensionally engaging a coil spring arranged circumferentially of said member and in bearing engagement with the outer surface of the restriction in said bore, said valve member comprising an internally threaded tubular inner part having an elongated shank loosely fitting within and passing through the restriction of said bore and terminating in said valve head portion at the inner end thereof, and an elongated externally threaded outer part axially interfltting with said inner part.

3. A pump mechanism as defined in claim 1, wherein the inward movement of said valve member is limited by contact with the inner end wall of the recess receiving said intake valve assemblage, and axially protruding means at the inner end of said valve head portion and within the transverse boundaries thereof maintaining transverse fluid passages between said valve head portion and the engaged inner end wall of said recess.

4. A pump mechanism as defined in claim 3, wherein the connecting passage registering with said intake valve recess is radially offset with respect to the axis of said valve member and protruding means, and the threaded portion of said outer part of the valve member extends beyond the inner part to contact the end wall of said recess.

5. A pump mechanism as defined in claim 3, wherein the connecting passage registering with said intake valve recess is in alignment with the axis of said valve member and registers with radial grooves in the end of said valve head forming circumferentially spaced projecting means.

6. An intake valve assemblage comprising a generally tubular body part having axially spaced external and circumferential flange and groove means facilitating detachable engagement with a recessed pump housing, said circumferential groove means being inwardly of said flange means providing adjacent the inner end of said body an annular recess for receiving a resilient ring-like seal member, said body having an axial bore extending therethrough having a uniform diameter throughout the major portion thereof but including a restricted portion of reduced diameter at the inner portion thereof in general alignment with said external an nular recess, and a portion of enlarged diameter inwardly of said reduced diameter portion for reception of a ring-like resilient valve seat, a two part valve member arranged within said bore, the inner part of said valve member comprising an essentially tubular and internally threaded member having an enlarged inner valve head end circumferentially contoured to interfit with said valve seat, and an outwardly extending shank of a length sufficient to extend through the restricted portion of said bore and of a diameter to provide free fluid passage between said shank and the restricted portion of said bore, the outer part of said valve member comprising an elongated cylindrical body having substantially the diameter of the shank of said inner part and including a reduced axial extension externally threaded to interfit with said first part, an elongated coil spring co-axially arranged in the space between the bore of said valve body and the inner part of said valve member with the inner end thereof bearing against the outer end of the restricted portion of said bore, and radially protruding means at the outer end portion of the outer part of said valve member engaging the outer end of said spring to maintain the same under compression, thereby supporting the valve head in yieldable engagement with said valve seat.

7. An intake valve assemblage as defined in claim 6, wherein said radially protruding means comprises a split ring detachably interfitting with an annular groove at the outer end portion of said valve member.

8. An intake valve assemblage as defined in claim 9, wherein the enlarged diameter portion of the bore of said valve body terminates short of the inner end of said body providing positive positioning of said ring-like resilient valve seat.

9. An intake valve assemblage as defined in claim 6, wherein the inner valve head end of said valve member includes axially protruding bearing means within the transverse boundaries of said valve head providing stop engagement against the end wall of a valve recess while providing radial fluid passage between said valve head and end wall.

10. An intake valve assemblage as defined in claim 9, wherein said bearing means comprises an extension of the outer valve part protruding beyond the inner end of said inner valve part for contact with an end wall having a fluid port 'radially offset with respect to the axis of said valve member.

1 1. An intake valve assemblage as defined in claim 9, wherein said bearing means comprises a plurality of communicating radial grooves forming circumferentially spaced projections at the end of said valve member for bearing engagement with an end wall having a fluid port in alignment with the axis of said valve member. 

1. A pump mechanism comprising a housing forming an elongated closed end chamber having a piston closely engaging the side walls of said chamber and reciprocating toward and from said closed end, said housing having circumferentially spaced recesses extending radially of said chamber in alignment with the closed end thereof for detachably receiving inlet and outlet valve assemblages, said recesses communicating with said chamber through short radial passages having aligned sides coextensive with the closed end of said chamber, each of said valve assemblages including spring tensioned valve means having seating means closely adjacent the respective inlet and outlet passages, the spring tensioning means for both the inlet and outlet valves being disposed within the respective valve assemblage with the seating means between the tensioning means and the respective passages, orientation of the valve tensioning means in the intake valve assemblage being provided by a valve insert having a generally cylindrical bore extending therethrough with an annular restriction of reduced diameter adjacent the inner end of said bore providing the fluid passage of said intake valve, and an elongated valve member freely and axially movable in said bore, said movable member having an enlarged diameter valve head portion at the inner end thereof cooperating with the inner surface of said restriction to provide a valve seat, the opposite end of said member having radially extending means for tensionally engaging a coil spring arranged circumferentially of said member and in bearing engagement with the outer surface of the restriction in said bore, the bore of said intake valve insert receiving an annular resilient member in engagement with the inner surface of said restriction and providing a valve seat for engagement with the valve head portion of said axially movable member, and the bore of said intake valve insert having an annular recess of enlarged diameter adjacent the inner surface of said restriction providing interlocked engagement between said annular resilient member and said intake valve insert.
 2. A pump mechanism comprising a housing forming an elongated closed end chamber having a piston closely engaging the side walls of said chamber and reciprocating toward and from said closed end, said housing having circumferentially spaced recesses extending radially of said chamber in alignment with the closed end thereof for detachably receiving inlet and outlet valve assemblages, said recesses communicating with said chamber through short radial passages having aligned sides coextensive with the closed end of said chamber, each of said valve assemblages including spring tensioned valve means having seating means closely adjacent the respective inlet and outlet passages, the spring tensioning means for both the inlet and outlet valves being disposed within the respective valve assemblage with the seating means between the tensioning means and the respective passages, orientation of the valve tensioning means in the intake valve assemblage being provided by a valve insert having a generally cylindrical bore extending therethrough with an annular restriction of reduced diameter adjacent the inner end of said bore providing the fluid passage of said intake valve, and an elongated valve member freely and axially movable in said bore, at the inner end thereof cooperating with the inner surface of said restriction to provide a valve seat, the opposite enD of said member having radially extending means for tensionally engaging a coil spring arranged circumferentially of said member and in bearing engagement with the outer surface of the restriction in said bore, said valve member comprising an internally threaded tubular inner part having an elongated shank loosely fitting within and passing through the restriction of said bore and terminating in said valve head portion at the inner end thereof, and an elongated externally threaded outer part axially interfitting with said inner part.
 3. A pump mechanism as defined in claim 1, wherein the inward movement of said valve member is limited by contact with the inner end wall of the recess receiving said intake valve assemblage, and axially protruding means at the inner end of said valve head portion and within the transverse boundaries thereof maintaining transverse fluid passages between said valve head portion and the engaged inner end wall of said recess.
 4. A pump mechanism as defined in claim 3, wherein the connecting passage registering with said intake valve recess is radially offset with respect to the axis of said valve member and protruding means, and the threaded portion of said outer part of the valve member extends beyond the inner part to contact the end wall of said recess.
 5. A pump mechanism as defined in claim 3, wherein the connecting passage registering with said intake valve recess is in alignment with the axis of said valve member and registers with radial grooves in the end of said valve head forming circumferentially spaced projecting means.
 6. An intake valve assemblage comprising a generally tubular body part having axially spaced external and circumferential flange and groove means facilitating detachable engagement with a recessed pump housing, said circumferential groove means being inwardly of said flange means providing adjacent the inner end of said body an annular recess for receiving a resilient ring-like seal member, said body having an axial bore extending therethrough having a uniform diameter throughout the major portion thereof but including a restricted portion of reduced diameter at the inner portion thereof in general alignment with said external annular recess, and a portion of enlarged diameter inwardly of said reduced diameter portion for reception of a ring-like resilient valve seat, a two part valve member arranged within said bore, the inner part of said valve member comprising an essentially tubular and internally threaded member having an enlarged inner valve head end circumferentially contoured to interfit with said valve seat, and an outwardly extending shank of a length sufficient to extend through the restricted portion of said bore and of a diameter to provide free fluid passage between said shank and the restricted portion of said bore, the outer part of said valve member comprising an elongated cylindrical body having substantially the diameter of the shank of said inner part and including a reduced axial extension externally threaded to interfit with said first part, an elongated coil spring co-axially arranged in the space between the bore of said valve body and the inner part of said valve member with the inner end thereof bearing against the outer end of the restricted portion of said bore, and radially protruding means at the outer end portion of the outer part of said valve member engaging the outer end of said spring to maintain the same under compression, thereby supporting the valve head in yieldable engagement with said valve seat.
 7. An intake valve assemblage as defined in claim 6, wherein said radially protruding means comprises a split ring detachably interfitting with an annular groove at the outer end portion of said valve member.
 8. An intake valve assemblage as defined in claim 9, wherein the enlarged diameter portion of the bore of said valve body terminates short of the inner end of said body providing positive positioning of said ring-like resilient valve seat.
 9. An iNtake valve assemblage as defined in claim 6, wherein the inner valve head end of said valve member includes axially protruding bearing means within the transverse boundaries of said valve head providing stop engagement against the end wall of a valve recess while providing radial fluid passage between said valve head and end wall.
 10. An intake valve assemblage as defined in claim 9, wherein said bearing means comprises an extension of the outer valve part protruding beyond the inner end of said inner valve part for contact with an end wall having a fluid port radially offset with respect to the axis of said valve member.
 11. An intake valve assemblage as defined in claim 9, wherein said bearing means comprises a plurality of communicating radial grooves forming circumferentially spaced projections at the end of said valve member for bearing engagement with an end wall having a fluid port in alignment with the axis of said valve member. 